Previous cardiac monitors performed only a few monitoring activities and were therefore unsuitable for many monitoring functions. For example, some monitors such as Ambos et al. U.S. Pat. No. 4,680,708, store heartbeat waveforms and generate an average waveform therefrom but do not compare these average waveforms or detect anomalies as the instant invention does.
In monitors that make a comparison between an incoming waveform and a stored waveform, none disclose use of the average waveform for the stored waveform For example, the information stored in Lester et al. U.S. Pat. No. 4,129,125 is merely of "normal" readings programmed into the ROM by operator.
Some monitors, like Schlager U.S. Pat. No. 4,193,393, while having the capability to store anomalous heartbeat waveforms, as this invention does, do not have the ability to compare incoming and average pulse rates and energize an alarm when a predetermined number of beats are skipped
As can be seen, the prior art does not have the capability to perform a multiple of important monitoring activities required for thorough surveillance of primate cardiac patients. Consequently, there is a great need for a cardiac monitoring device which can supply all needed monitoring functions in an inexpensive, compact and easy to use device.